All 16 victims were taken to hospitals and eventually listed in stable condition, but it's unclear how many were shot.

The shooting broke out at an after-party for an annual second line parade by the Nine Times Social & Pleasure Club, a community group in the city's mostly African-American Ninth Ward. It apparently stemmed from an argument that broke out during the impromptu filming of a music video, WWLTV reported.

"At the end of the day it's really hard to police against a bunch of guys who decide to pull out guns and settle disputes with 300 people between them," Mayor Mitch Landrieu told reporters on the scene.

The party and the filming did not have permits, authorities said.

The shooting occurred at Bunny Friend Park in New Orleans. (Google Maps)